1. Field of the Invention
The invention is directed to method of protecting a fiber optic probe and the resulting fiber optic probe.
2. Background of the Related Art
Optical fibers and collections or bundles of such optical fibers are now commonly used for illumination, remote viewing and remote spectroscopy in, for example, medicine, industry and science. The function of a particular optical fiber in a bundle can be illumination of a subject or collection of light from a subject or sample for remote viewing or spectroscopic analysis of the light returned. It is common practice to use a binding agent, adhesive or epoxy material to hold the optical fibers together and in place within a probe housing. Once fixed in place, it is common practice to polish the ends of the optical fibers, and therefore the binding agent and the housing, to a common surface level.
For example, FIG. 1 shows an exemplary endoscope 1 employing a fiber optic probe 10. The endoscope 1 includes a transmit optical fiber bundle 20a, which conveys excitation electromagnetic radiation from a radiation source 2 to a target tissue. The endoscope 1 further includes a return optical fiber bundle 20b for communicating reflected/scattered electromagnetic radiation or fluorescent emissions from a target tissue to a detector 3. The transmit and return optical fibers can be co-located; or can be the same optical fibers. The endoscope may further include a handle 4 for positioning the fiber optic probe 10.
FIG. 1B shows the structure of fiber optic probe 10 of the endoscope 1. The apparatus includes a housing 60 having a long body portion 5, which is intended to be inserted into a body of a patient. The body portion 5 may have a diameter that is sufficiently small so that the body portion 5 can be inserted into blood vessels, or a natural lumen or body cavity of a patient.
As shown in FIG. 2, each optical fiber contains a core 20a, preferably formed of glass or plastic, and a cladding 20b, preferably formed of doped glass or plastic. The optical fibers 20 may also include a buffer 20c and/or a jacket 20d, preferably formed of protective materials, such as, for example, plastic or polyimide. As shown in FIGS. 1B, 1C and 2, the optical fibers 20 are bundled using a binding agent 30.
A microscopic examination of a fiber optic probe that has been constructed and polished as discussed above, frequently reveals that the binding agent and optical fiber components are not at the same height. Either the materials are polished back further due to their softer nature, or the materials shrink back upon aging. As shown in FIG. 2, which shows the face 15 of the fiber optic probe 10 of FIG. 1, this creates spaces 35 between the ends or faces of the optical fibers 36 and the binding agent 30 where contaminants 40, such as bits of dust, polishing compound, adhesive residue and the like can collect. When the ends of such optical fibers 26 are wiped for cleaning, the materials collected in these spaces may be moved to the ends or faces of the optical fibers 36 and leave the fiber faces 36 with more dirt and residue than before cleaning.
In addition, there are materials in medicine and industry which one would like to minimize collecting on the probe in the void spaces or on the surfaces of the fibers.
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
According to a preferred embodiment of the invention, a fiber optic probe comprises a housing, at least one optical fiber disposed within the housing, one end of each of the at least one optical fiber being disposed adjacent an opening in the housing forming a probe face, a binding agent that binds the at least one optical fiber within the housing, and a protective coating sealingly covering the probe face to prevent contaminants from contacting the at least one optical fiber. The at least one optical fiber may comprise a plurality of optical fibers, and the protective coating may sealingly cover portions of the binding agent located between the plurality of optical fibers.
The protective coating is preferably formed of an adhesive, an epoxy or a polymer. The binding agent is also preferably formed of an adhesive, an epoxy and a polymer. The protective coating is preferably polished so that a cone angle of the at least one optical fiber is preserved, or is substantially the same as a cone angle that the at least one optical fiber has without the protective coating.
The at least one optical fiber may receive light from a greater subject surface area with the protective coating than without the protective coating. Further, the at least one optical fiber may illuminate a greater subject surface area with the protective coating than without the protective coating.
Further, a preferred method embodying the invention for protecting a fiber optic probe that includes a housing, at least one optical fiber disposed within the housing, one end of the optical fiber being disposed adjacent an opening in the housing forming a probe face, and a binding agent that binds the at least one optical fiber within the housing, comprises polishing the probe face, cleaning the probe face after polishing the probe face, and sealing the probe face with a protective coating. The method may further comprise polishing the protective coating. The step of polishing the protective coating may comprise polishing the protective coating to control the spot size of the at least one optical fiber. The step of cleaning the probe face may comprise ultrasonic cleaning, or flooding the probe head with at least one of water and solvent at normal or high pressure.
The protective coating is preferably formed of an adhesive, an epoxy and/or a polymer. The protective coating is preferably polished so that a cone angle of the at least one optical fiber is preserved. Further, the protective coating may be configured so that the at least one optical fiber receives light from a greater subject surface area with the protective coating than without the protective coating. Furthermore, the protective coating may be configured so that the at least one optical fiber illuminates a greater subject surface area with the protective coating than without the protective coating.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.